Lifesteal with crits
Not even gonna bring up warlord's, just here to talk about how ridiculous lifesteal is with crits.
It wasn't so bad when adc were only getting around 60% crit chance, but now with carries getting 80-100% crit chance and sometimes two lifesteal items, something has to be done.
Simply put, the healing is too damn much when champions crit. When they crit, they're hitting for like 700 damage minimum with IE. With just 20% lifesteal, that's healing for 140 per auto. Again, not so bad before, but now they're critting on every attack and attacking at 2 attacks per second so it's a bit on the strong side.